Method of and means for recovering metals from their ores



Dec. 29, 1964 w. CHAMBERS 3,163,591

METHOD OF AND MEANS FOR RECOVERING METALS FROM THEIR ORES Filed Oct. 20,1961

INVENT OR T L 3 R w. CHAMBERS ATTORNEYS United States This invention relates to a method of and means for recovering metals from ores.

One of its objects is to elfect the recovery in the form of a metal sheet which is deposited upon a revolving cylinder and may be stripped therefrom in sheet form as the metal recovery proceeds.

I am aware of the fact that it is old to bring about the formation of thin sheets upon the surface of a revolving cylinder, through an electrolytic plating operation, in which the metal treated is introduced in its complete form into the electrolyte, the said metal being then deposited in thin sheet form upon the surface of the cylinder and, if desired, continuously stripped from the cylinder by being wound into a roll.

My invention differs from the foregoing in that it aims to initially recover the metal from the raw ores in which it is found and to do this in a more expeditious and efiicient way than has heretofore been known.

The invention will be best understood by reference to the accompanying drawing wherein:

FIG. 1 is a transverse, vertical sectional view of a metal recovery apparatus with parts in elevation and with an ore crusher diagrammatically illustrated in association therewith;

FIG. 2 is a perspective view of the carrying elements of carbon anode bars, hereinafter described; and

FIG. 3 is a fragmentary view illustrating the bearing support for the shaft of the cylinder and anode bar carrier removed.

Like numerals designate corresponding parts in all of the figures of the drawing.

In the drawing, 5 designates a tank which may be made of stainless steel, wood or other suitable material. An inlet trough 6 extends along one side of the tank near its top and an outlet trough 7 extends along the other side of the tank with its top slightly below the level of trough 6. A supply pipe 8 discharges into trough 6 a slurry consisting of water and the crushed ore from an ore crusher 9, water being introduced through pipe 9' into the ore crusher during the crushing operation. A suitable quantity of sulphuric acid is supplied to the slurry to cause it to function as an electrolyte when it is passed between the anode and cathode of an electrolytic plating apparatus. The cathode employed is in the form of a rotative cylinder 10 and the anode consists of a pair of heavy carbon bars 11. The tank carries insulated bemings 12 at its ends (only one of which is shown) in which bearings the supporting shaft 13 of the cylinder rotates. This shaft may be rotated by belt and pulley 13a, 13b. The carbon bars extend along the underside of the cylinder, lying in spaced relation thereto. These anode bars are supported by stirrups 14 which stirrups comprise supporting bars 15, said bars in turn being supported upon the upper edge of the tank, and being insulated therefrom. One bar 15 carries a contact post 16 to which the positive cable 17 of an electric circuit is connected. The

negative cable 18 of said circuit leads to one of the bearings 12' and thus completes a plating circuit through the anode bars, electrolytic ore bearing slurry and the cathode forming cylinder 10.

If a copper bearing slurry of raw copper ore be passed from trough 6 to trough 7 the copper will be deposited as a sheet upon the surface of the cylinder and may be atent 3,ld3,59l Patented Dec. 29., I964 current path at this most critical point and speeds up the a rate of copper recovery.

While I have described the use of the device in recovering copper from copper ores it is clear that other metals may be extracted from their ores in like manner.

' Further, while I have described the cathode as being in the form of a rotative cylinder, another form of traveling cathode forming surface could be used if desired.

A take-off pipe 20 leads from the trough 7 and while the spent ore could be cast off through this pipe, I may return the slurry from this pipe to trough 6 whereby to pass said slurry one or more times through the metal extractor until tests show that practically all of the valuable metal content has been recovered. After the device has been in use, it forms its own sulphuric acid to maintain the slurry in electrolyte forming condition. Since, as stated, the inlet trough 6 lies at a higher. level than the outlet trough 7, the slurry of water and comminuted ore is caused to move in a path from trough 6 to trough 7 and transversely of the axis of the rotating cylinder 10. In doing this, the slurry sweeps over the bottom of the cathode forming cylinder 10. The body of mercury 19 is maintained by gravity at the bottom of the cylinder. There, as previously stated, it adds to the mass or volume of the current path in this zone of greatest plating activity over which the slurry is moving, as it travels from trough 6 to trough '7. This increase in the volume or mass of the current path increases the rate of metallic particle recovery much beyond the rate of recovery which would take place if only the thickness of the cylinder walls were presented to the slurry at that point.

The amount of mercury employed is not critical. The

amount employed may be varied within relatively wide ranges. An amount in about the proportions indicated in FIG. 1 has been found to yield a marked increase in the rate of recovery of themetallic content of the ore. Even asrnall amount of mercury will yield some increase in recovery of the metallic content of the slurry. The mercury will be in such amount as to provide a flowable, electrically conductive body which is maintained by gravity at the bottom of the cylinder and at a point opposite the anode.

. It is to be understood that the invention is not limited to the particular apparatus shown but that it includes within its purview whatever changes fall within either the terms or the spirit of the appended claims.

I claim:

1. In an apparatus for recovering the metallic content of ores, a liquid receiving tank, a closed cylinder cathode mounted for rotation about a longitudinal axis within said tank, an anode-forming element located within the tank and lying in spaced relation to the underside of said cylinder, an inlet trough extending along the tank at one side thereof, an outlet trough extending along the tank at the other side thereof, means for feeding a slurry of water and comminuted metal-bearing ore into the inlet trough, said slurry having a pH content to constitute it an electrolyte, said outlet trough being disposed at a lower level than the inlet trough, whereby a flow of the slurry in its passage from the inlet to the outlet trough is set up in a path below and transversely of the axis of rotation of the cylinder, and a body of mercury disposed in said cylinder and gravitationally maintained at a point opposite to the anode forming element.

2. In an apparatus for recovering the metallic content of ores, a liquid receiving tank, a closed cylinder cathode mounted for rotation. about a longitudinal axis within said tank, an anode forming element located within the tank and lying in spaced relation to the underside of said cylinder, means for feeding a slurry of water and comminuted metal-bearing ore into said tank at one side thereof and along its length, said slurry having a pH content adapting it to constitute an electrolyte, means for conducting the slurry, after the removal of the metallic content thereof, from the opposite side of the tank at a point lower than the level at which the slurry is fed into the tank, whereby a flow of the slurry is set up in a path transversely of and beneath said cylinder, and a fiowable body of mercury gravitationally maintained in the lower part of the cylinder during its rotation and at a point substantially opposite the anode forming element, the presence of said mercury increasing the mass of electrically conductive material in the cathode materially beyond the mass that would be presented by the cylinder wall alone in the absence of the body of mercury, said mercury being in an amount materially less than the amount required to fill said cylinder.

3. The herein described electrolytic method of increasing the recovery rate of metals from their raw ores which consists of passing a slurry of water and comminuted raw ore between a hollow, closed rotative cathode and an anode, while gravitationally maintaining a body of mercury within said rotative cathode at a point opposite the anode and throughout the rotation of said cathode, said slurry having a pH content to constitute it an electrolyte.

4. The herein described electrolytic method of increasing the recovery rate of metals from their raw ores which consists of passing a slurry of water and cornminuted raw ore between a hollow, closed rotative cathode and an anode throughout the rotation of the cathode, while gravitationally maintaining a body of fiowable, highly conductive liquid metal within the closed, hollow rotative cathode and the anode throughout the rotation of said cathode.

References Cited in the file of this patent UNITED STATES PATENTS 1,296,523 Irving Mar. 4, 1919 1,447,140 McBride Feb. 27, 1923 1,601,691 Merritt Sept. 28, 1926 2,322,796 Fentress June 29, 1943 2,351,586 Coulson June 20, 1944 2,446,548 Nachtman Aug. 10, 1948 2,782,159 Berry Feb. 19, 1957 2,944,954 Yeck July 12, 1960 

1. IN AN APPARATUS FOR RECOVERING THE METALLIC CONTENT OF ORES, A LIQUID RECEIVING TANK, A CLOSED CYLINDER CATHODE MOUNTED FOR ROTATION ABOUT A LONGITUDINAL AXIS WITHIN SAID TANK, AN ANODE-FORMING ELEMENT LOCATED WITHIN THE TANK AND LYING IN SPACED RELATION TO THE UNDERSIDE OF SAID CYLINDER, AN INLET TROUGH EXTENDING ALONG THE TANK AT ONE SIDE THEREOF, AN OUTLET TROUGH EXTENDING ALONG THE TANK AT THE OTHER SIDE THEREOF, MEANS FOR FEEDING A SLURRY OF WATER AND COMMINUTED METAL-BEARING ORE INTO THE INLET TROUGH, SAID SLURRY HAVING A PH CONTENT TO CONSISTUTE IT AN ELECTROLYTE, SAID OUTLET TROUGH BEING DISPOSED AT A LOWER LEVEL THAN THE INLET TROUGH, WHEREBY A FLOW OF THE SLURRY IN ITS PASSAGE FROM THE INLET TO THE OUTLET TROUGH IS SET IN ITS PASSAGE FROM THE INLET TO THE OUTLET TROUGH IS SET UP IN A PATH BELOW AND TRANSVERSELY OF THE AXIS OF ROTATION OF THE CYLINDER, AND A BODY OF MERCURY DISPOSED IN SAID CYLINDER AND GRAVITATIONALLY MAINTAINED AT A POINT OPPOSITE TO THE ANODE FORMING ELEMENT.
 4. THE HEREIN DESCRIBED ELECTROLYTIC METHOD OF INCREASING THE RECOVERY RATE OF METALS FROM THEIR RAW ORES WHICH CONSISTS OF PASSING A SLURRY OF WATER AND COMMUNINUTED RAW ORE BETWEEN OF HOLLOW, CLOSED ROTATIVE CATHODE AND AN ANODE THROUGHOUT THE ROTATION OF THE CATHODE, WHILE GRAVITATIONALLY MAINTAINING A BODY OF FLOWABLE, HIGHLY CONDUCTIVE LIQUID METAL WITHIN THE CLOSED, HOLLOW ROTATIVE CATHODE AND THE ANODE THROUGHOUT THE ROTATION OF SAID CATHODE. 